TRILL, which stands for TRansparent Interconnect of Lots of Links, is an IETF standard that is implemented by devices referred to as routing bridges (“RBridges”) or TRILL switches. An RBridge is a network device that implements the TRILL protocol and is compatible with previous IEEE 802.1 bridges, as well as IPv4 and IPv6 routers and end nodes. RBridges are invisible to current IP routers and, like such routers, terminate the bridge Spanning Tree Protocol (“STP”). RBridges in a campus share connectivity information amongst themselves using Intermediate System to Intermediate System (“IS-IS”) link state protocol. Via IS-IS, connectivity is broadcast to all RBridges so that each RBridge is aware of all of the other RBridges as well as the connectivity therebetween. As a result, RBridges can compute pair-wise optimal paths for unicast frames, as well as distribution trees for unknown or multicast/broadcast frames.
TRILL combines the advantages of bridges and routers and is the application of link state routing to the VLAN-aware customer-bridging problem. Border Gateway Protocol (“BGP”) is the protocol that makes core routing decisions on the Internet. A relatively new architecture for data center networking called Vinci has recently been introduced. The physical topology of this architecture is based on a two-tier fat-tree, where every leaf switch is connected to every spine switch and vice versa. In this architecture, TRILL may be used to enable data forwarding while BGP may be used for route distribution among leafs, via route reflectors (“RR”).